Establishment Clause of the First Amendment

The Anti-Establishment Clause, also sometimes confusingly labelled the Establishment Clause or the Religion Clause, is the first of several pronouncements in the First Amendment to the United States Constitution, stating,

Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof...

The Anti-Establishment Clause was derived from a number of precursors, including the Constitutions of Clarendon, the 1689 Bill of Rights, the Pennsylvania and New Jersey colonial constitutions. An initial draft by John Dickinson was prepared in conjunction with his drafting the Articles of Confederation. In 1789, then-congressman James Madison prepared another draft which, following discussion and debate in the First Congress, would become incorporated into the First Amendment of the Bill of Rights. The second half of the Anti-Establishment Clause includes the Free Exercise Clause, which allows individual citizens freedom from governmental interference in both private and public religious affairs.

The Anti-Establishment Clause is a limitation placed upon the United States Congress preventing it from passing legislation respecting an establishment of religion. The second half of the Anti-Establishment Clause inherently prohibits the government from preferring any one religion over another. While the Anti-Establishment Clause does prohibit Congress from preferring or elevating one religion over another, it does not prohibit the government's entry into the religious domain to make accommodations for religious observances and practices in order to achieve the purposes of the Free Exercise Clause.

The Constitutions of Clarendon, an 11th Century English law, had prohibited criminal defendants using religious laws (primarily those of the Catholic Church) to seek exemption from criminal prosecution.

The 1689 English Bill of Rights secured the rights of all "persons" to be free from establishment of Catholic Church laws in the government of England.

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